1. Field of the Invention
The present invention relates to a suction recovery mechanism and an ink jet recording apparatus using the same.
2. Description of the Related Art
Recording apparatuses, such as printers, copying apparatuses and facsimile machines form images on a recording material, such as paper or a plastic thin sheet, on the basis of image information.
Such recording apparatuses are classified according to their recording methods into several types, including an ink jet type, a wire dot type, a thermal type and a laser beam type. Ink jet recording apparatuses operate in such a way that ink is discharged through openings in recording heads onto recording materials so as to perform recording.
An ink jet recording apparatus has the following advantages: it can easily record fine and delicate color images at a high speed by using color inks, and it generates little noise because it employs a non-impact system for recording.
Ink jet recording apparatus is equipped with an ink tank for retaining ink and a recording head through which the ink is discharged to perform recording. A cartridge-type recording head, in which an ink tank and recording head are formed integrally, is widely employed as a replaceable recording head.
When such a type of ink jet recording apparatus is not performing a recording operation, the recording head is tightly closed, or capped, so that the ink in a discharge opening does not dry out. Consequently, the opening is prevented from clogging.
An air communicating or vent opening is formed in the ink tank to keep pressure inside the tank constant while the recording apparatus is performing a recording operation. When the apparatus is not performing a recording operation, the vent opening must also be capped to prevent the ink from evaporating.
The structure of a conventional ink jet recording apparatus is such that when the recording head discharge opening is capped, the ink tank vent opening is simultaneously capped.
In such a structure, however, when the ink increases in viscosity or adheres to the discharge opening, thus clogging the opening, it is impossible or difficult to suck ink through the discharge opening to recover a proper recording condition because negative pressure is generated in the ink tank.